Mechanism modeling of microwave‐induced relative volatility change via molecular thermodynamics

Abstract Although there is a significant strengthening effect, the unclear intrinsic mechanism of microwave (MW)‐enhanced vapor–liquid mass transfer separation has hindered its refined application in chemical separation processes. To address this issue, we elucidate this intensification mechanism from a molecular thermodynamic perspective, integrating molecular‐scale microwave selective heating with macroscopic vapor–liquid equilibrium theory. Our analysis reveals that molecular aggregates overheating and evaporative kinetic energy increase induced by microwave selective heating are the primary drivers of the MW‐induced relative volatility change (MIRVC) effect. The developed thermodynamic model demonstrates that the MIRVC effect is co‐regulated by the binary system's thermodynamic properties, dielectric characteristics, and microwave field intensity. The strong agreement between model predictions and experimental results from MW‐induced distillation separation robustly validates the reliability of the MIRVC thermodynamic model, providing fundamental insights and design principles for the precise application of MW‐enhanced vapor–liquid mass transfer in chemical separation, thereby advancing low‐carbon and high‐efficiency chemical production.